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-rw-r--r--kernel/time/tick-sched.c28
-rw-r--r--kernel/time/timer_list.c1
2 files changed, 29 insertions, 0 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 50953f4c42b2..1d7b9bc1c034 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -161,6 +161,8 @@ update_ts_time_stats(struct tick_sched *ts, ktime_t now, u64 *last_update_time)
if (ts->idle_active) {
delta = ktime_sub(now, ts->idle_entrytime);
ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
+ if (nr_iowait_cpu() > 0)
+ ts->iowait_sleeptime = ktime_add(ts->iowait_sleeptime, delta);
ts->idle_entrytime = now;
}
@@ -220,6 +222,32 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
}
EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
+/*
+ * get_cpu_iowait_time_us - get the total iowait time of a cpu
+ * @cpu: CPU number to query
+ * @last_update_time: variable to store update time in
+ *
+ * Return the cummulative iowait time (since boot) for a given
+ * CPU, in microseconds.
+ *
+ * This time is measured via accounting rather than sampling,
+ * and is as accurate as ktime_get() is.
+ *
+ * This function returns -1 if NOHZ is not enabled.
+ */
+u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
+{
+ struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+
+ if (!tick_nohz_enabled)
+ return -1;
+
+ update_ts_time_stats(ts, ktime_get(), last_update_time);
+
+ return ktime_to_us(ts->iowait_sleeptime);
+}
+EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us);
+
/**
* tick_nohz_stop_sched_tick - stop the idle tick from the idle task
*
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 1a4a7dd78777..ab8f5e33fa92 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -176,6 +176,7 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now)
P_ns(idle_waketime);
P_ns(idle_exittime);
P_ns(idle_sleeptime);
+ P_ns(iowait_sleeptime);
P(last_jiffies);
P(next_jiffies);
P_ns(idle_expires);